// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_GFX_ANIMATION_ANIMATION_CONTAINER_ELEMENT_H_
#define UI_GFX_ANIMATION_ANIMATION_CONTAINER_ELEMENT_H_

#include "base/time/time.h"
#include "ui/gfx/gfx_export.h"

namespace gfx {

// Interface for the elements the AnimationContainer contains. This is
// implemented by Animation.
class GFX_EXPORT AnimationContainerElement {
public:
    // Sets the start of the animation. This is invoked from
    // AnimationContainer::Start.
    virtual void SetStartTime(base::TimeTicks start_time) = 0;

    // Invoked when the animation is to progress.
    virtual void Step(base::TimeTicks time_now) = 0;

    // Returns the time interval of the animation. If an Element needs to change
    // this it should first invoke Stop, then Start.
    virtual base::TimeDelta GetTimerInterval() const = 0;

protected:
    virtual ~AnimationContainerElement() { }
};

} // namespace gfx

#endif // UI_GFX_ANIMATION_ANIMATION_CONTAINER_ELEMENT_H_
